Foil-Wound Inductor Assembly for Compact Overvoltage Insulation

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Solution Overview

Problem

Conventional inductor coil designs are large in size and unable to withstand significant transient overvoltages, with minimal contact between turns leading to potential movement and reduced durability, and they require a significant conductor cross-section for load current, resulting in space loss between turns.

Innovation Solution

A dual coil inductor assembly with spirally wound metal foil and insulator layers, where the foil and insulator are not bonded during winding, and are surrounded by an epoxy resin for enhanced insulation, with terminal bus bars and a compact enclosure to minimize size and withstand vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If conventional inductor coil designs are used, then the inductor can provide necessary inductance, but the size is large and space is wasted between turns

Engineering Contradiction:
Improveinductor sizeVSAvoidwithstand transient overvoltages
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent segments the conductor into multiple thin foils (first conductor foil and second conductor foil) wound in parallel, replacing a single thick conductor. This segmentation allows tighter winding with minimal gaps between turns while maintaining the required current carrying capacity, thus reducing inductor size without compromising reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite construction by combining multiple conductor foils with insulating layers between them. This composite structure enables efficient space utilization through tight winding while providing enhanced insulation and electrical stability, addressing both size reduction and transient overvoltage withstand requirements

Inventive Principle:
Principle #40Composite materials

2Device complexity

If minimal contact between turns is used, then the inductor structure is simpler, but movement and durability are reduced

Engineering Contradiction:
Improvecoil structureVSAvoiddurability against movement
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The patent divides the conductor into multiple thin foils that can be tightly wound in parallel. The segmented structure naturally provides better contact between adjacent turns due to the flexibility and thinness of individual foils, enhancing mechanical stability without significantly increasing structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines multiple conductor foils with insulating layers into an integrated winding assembly. This merging of components creates a compact, stable structure where the foils are held firmly in place by the insulating layers and the winding tension, improving durability while maintaining relatively simple construction

Inventive Principle:
Principle #5Merging (Combining)

3Power

If significant conductor cross-section is used for load current, then the current carrying capacity is sufficient, but space loss between turns increases

Engineering Contradiction:
Improveload current capacityVSAvoidspace between turns
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent segments the current path into multiple parallel foil conductors. Each thin foil carries a portion of the total load current, and the combined cross-sectional area of all foils equals or exceeds the required current carrying capacity. This segmentation allows the foils to be wound tightly with minimal gaps, eliminating space loss while maintaining sufficient power handling capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from using a single thick conductor (one-dimensional approach) to multiple thin foils wound in parallel (multi-dimensional arrangement). This dimensional change enables efficient packing of conductor material, maximizing the use of available space for current-carrying material while minimizing voids and gaps between turns

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design provides improved insulation and stability against transient overvoltages, reduces size, and enhances durability by minimizing air gaps and preventing flashover, while maintaining a compact footprint and low weight.

Implementation Method 1

the metal foil and the electrical insulator layer are not bonded to one another across their widths... surrounded by an epoxy resin for enhanced insulation, with terminal bus bars and a compact enclosure to minimize size and withstand vibrations

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Data Source

PatentEP4339976B1Inductor assemblies
Publication Date: 2025.01.01 RAYCAP SA
  • EP4339976B1 patent drawingFigure 1
  • EP4339976B1 patent drawingFigure 2
  • EP4339976B1 patent drawingFigure 3

AI summary

An inductor assembly includes a coil including a spirally wound metal foil.